[NTP Snippets] Schedule periodic fetching

chrome/android/java/src/org/chromium/chrome/browser/ChromeGcmTaskService.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser;
+
+import android.content.Context;
+
+import com.google.android.gms.gcm.GcmNetworkManager;
+import com.google.android.gms.gcm.GcmTaskService;
+import com.google.android.gms.gcm.TaskParams;
+
+import org.chromium.base.Log;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.annotations.SuppressFBWarnings;
+import org.chromium.base.library_loader.LibraryProcessType;
+import org.chromium.base.library_loader.ProcessInitException;
+import org.chromium.chrome.browser.ntp.snippets.SnippetsController;
+import org.chromium.chrome.browser.ntp.snippets.SnippetsLauncher;
+import org.chromium.content.app.ContentApplication;
+import org.chromium.content.browser.BrowserStartupController;
+
+/**
+ * {@link GcmTaskService} is scheduled through the {@link GcmNetworkManager} when the browser needs
+ * to be launched for scheduled tasks, or in response to changing network or power conditions.
+ */
+public class ChromeGcmTaskService extends GcmTaskService {

[Bernhard Bauer, 2016/02/18 10:32:40]

Should we just name this ChromeBackgroundService? Using GcmTaskService is an
implementation detail.

[Marc Treib, 2016/02/18 10:52:40]

Done.

+    private static final String TAG = "ChromeGcmTaskService";
+
+    @Override
+    @VisibleForTesting
+    public int onRunTask(final TaskParams params) {
+        Log.i(TAG, "Woken up at " + new java.util.Date().toString());
+        final Context context = this;
+        ThreadUtils.runOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                switch(params.getTag()) {
+                    case BackgroundSyncLauncher.TASK_TAG:
+                        handleBackgroundSyncEvent(context);
+                        break;
+
+                    case SnippetsLauncher.TASK_TAG:
+                        handleFetchSnippets(context);
+                        break;
+                }
+            }
+        });
+        return GcmNetworkManager.RESULT_SUCCESS;
+    }
+
+    private void handleBackgroundSyncEvent(Context context) {
+        if (!BackgroundSyncLauncher.hasInstance()) {
+            // Start the browser. The browser's BackgroundSyncManager (for the active profile) will
+            // start, check the network, and run any necessary sync events. This task runs with a
+            // wake lock, but has a three minute timeout, so we need to start the browser in its
+            // own task.
+            // TODO(jkarlin): Protect the browser sync event with a wake lock.
+            // See crbug.com/486020.
+            launchBrowser(context);
+        }
+    }
+
+    private void handleFetchSnippets(Context context) {
+        if (!SnippetsLauncher.hasInstance()) {
+            launchBrowser(context);
+        }
+        SnippetsController.get(context).fetchSnippets(true);
+    }
+
+    @VisibleForTesting
+    @SuppressFBWarnings("DM_EXIT")
+    protected void launchBrowser(Context context) {
+        Log.i(TAG, "Launching browser");
+        ContentApplication.initCommandLine(context);
+        try {
+            BrowserStartupController.get(context, LibraryProcessType.PROCESS_BROWSER)
+                    .startBrowserProcessesSync(false);
+        } catch (ProcessInitException e) {
+            Log.e(TAG, "ProcessInitException while starting the browser process");
+            // Since the library failed to initialize nothing in the application
+            // can work, so kill the whole application not just the activity.
+            System.exit(-1);
+        }
+    }
+
+    @Override
+    public void onInitializeTasks() {
+        BackgroundSyncLauncher.rescheduleTasksOnUpgrade(this);
+    }
+}